Fu et al. (2026) Evapotranspiration-partitioned generalized complementary relationship model for heterogeneous vegetation

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-03-29
• Authors: Chong Fu, Weilin Liu, Xiaoyu Song, Lanjun Li, Lu Xia, Jing Yuan
• DOI: 10.1016/j.jhydrol.2026.135411

Research Groups

• Jiangxi Provincial Key Laboratory of Water Resources Allocation and Efficient Utilization, Jiangxi University of Water Resources and Electric Power, Nanchang, Jiangxi, China
• State Key Laboratory of Water Engineering Ecology and Environment in Arid Area, Xi’an University of Technology, Xi’an, Shaanxi, China
• College of Resources and Environment, Shanxi Agricultural University, Taigu, China
• Xifeng Experiment Station of Soil and Water Conservation, Yellow River Conservancy Committee, Qingyang, Gansu, China

Short Summary

This study proposes an evapotranspiration-partitioned generalized complementary relationship (EPGCR) model to estimate total evapotranspiration (ET) and its components (transpiration, soil evaporation, and interception evaporation) using only meteorological and leaf area index data. Applied to heterogeneous vegetation, the EPGCR demonstrated high accuracy and consistent parameters, significantly expanding the applicability of the complementary relationship.

Objective

• To propose and validate an evapotranspiration partitioning method, called the evapotranspiration-partitioned generalized complementary relationship (EPGCR), that can estimate total ET and its components (transpiration, soil evaporation, and interception evaporation) using only meteorological and leaf area index data, thereby expanding the application range of the complementary relationship.

Study Configuration

• Spatial Scale: Heterogeneous vegetation, specifically a Robinia pseudoacacia plantation and a natural grassland.
• Temporal Scale: A 10-year field experiment from 2015 to 2024.

Methodology and Data

• Models used: Evapotranspiration-partitioned generalized complementary relationship (EPGCR), dynamically scaled generalized complementary relationship (S2017), Beer equation, modified Priestley-Taylor equation.
• Data sources: Meteorological data, leaf area index (LAI) data, and 10-year field experiment data for validation.

Main Results

• The EPGCR model achieved high overall performance for total ET estimation with a Nash-Sutcliff Efficiency (NSE) of 0.75 during the validation period.
• The model maintained consistent parameters across different vegetation plots (plantation and grassland).
• High accuracy was observed for individual ET components: transpiration (NSE = 0.80), soil evaporation (NSE = 0.70), and interception evaporation (NSE = 0.71).
• The study demonstrated that the complementary relationship is applicable for estimating transpiration and soil evaporation, similar to total ET.
• It was found that interception evaporation does not exhibit a complementary relationship with its apparent potential term, which may be a source of error in traditional complementary relationship applications for total ET.

Contributions

• Developed a novel and simple model (EPGCR) that partitions total evapotranspiration into its components (transpiration, soil evaporation, and interception evaporation) requiring only meteorological and leaf area index data.
• Significantly expanded the potential application range of the generalized complementary relationship by enabling the estimation of individual ET components.
• Provided evidence that the complementary relationship framework is applicable for estimating transpiration and soil evaporation.
• Identified a critical insight that interception evaporation does not follow a complementary relationship, highlighting a potential error source in existing complementary relationship models for total ET.
• Offered a clear direction for the future development and refinement of complementary relationship models.

Funding

• Not specified in the provided text.

Citation

@article{Fu2026Evapotranspirationpartitioned,
  author = {Fu, Chong and Liu, Weilin and Song, Xiaoyu and Li, Lanjun and Xia, Lu and Yuan, Jing},
  title = {Evapotranspiration-partitioned generalized complementary relationship model for heterogeneous vegetation},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.135411},
  url = {https://doi.org/10.1016/j.jhydrol.2026.135411}
}